Horacio Lopez Menendez. Biophysics seminar ESPCI-ENS

20 April 2018 13:00 » 14:00 — A1 (Urbain)

Mechanical Instabilities and their role on apoptotic cell extrusion

The balance between cell division and live or apoptotic cell extrusion states the tissue homeostasis. It has strong implications in developmental processes such as morphogenesis and pathological processes like tumor spreading. Previous works showed that apoptotic cell extrusion occurs by the formation of a contractile ring created either by the neighboring cells or by the apoptotic cell. It has been reported that cell elimination in crowded tissue via the activation of Caspase demands drastic changes.

The relationship between the structural remodeling during the apoptosis and the extrusion process is not clear. We show that apoptotic cell extrusion within epithelial tissues arises from two mechanical instabilities, namely delamination, driven by the osmotic pressure, and cavity formation, driven by the cytoskeleton gel rupture. We show that the mechanical instabilities can play a major role in the regulation of the cell extrusion. Finally, we develop theoretical models that capture the physical origin of these observations. Our approach provides mechanisms that can lead to efficient apoptotic homeostatic regulation in epithelial tissues.

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